In electronic clocks calculators measuring instruments and some other scientific instruments LED are used to display the numerical digits. This display is made by seven LEDs. So it is called Seven Segment Display. In fig. below the schematic diagram and physical layout is shown.
In schematic diagram the seven LEDs are connected. The positive voltage is applied at the anode of all LEDs and when its cathode is connected with Ground (o) it will become ON condition and Emits light. If we connected the cathode of A,B & C with ground (o). So it shows seven (7) on the display. If A,B,C,D,E and G is connected to ground (o) it shows nine (9) on the display.
Seven Segment Display Applications
- It is widely used in digital clocks.
- In measuring instruments.
- Scientific instruments